Optical fibers are often used to deliver optical energy from an energy source to a work object or from a work object to a receiving apparatus. The optical energy can be used, for example, for imaging, illuminating, measuring or modifying the work object. In many applications the energy source is a laser and the optical fiber delivers laser light to the work object. For example, in an industrial setting a high power laser, such as a Nd YAG laser, can be used for cutting and/or welding, and an optical fiber can deliver the light from the Nd YAG laser to, for example, an automotive body for welding a seam on the body. Typically, a robotic arm moves one end of the optical fiber about for welding along the seam. As another example, in a medical setting an alexandrite laser can be used to remove unwanted hair from the body of a patient. Again an optical fiber delivers the light from the alexandrite laser to the patient. A physician can grasp one end of the fiber and direct light to a particular region of the patient's body. In yet a further example, an optical fiber can deliver light to a gaseous work object for performing, for example, Raman spectroscopy on the object. In this instance a detector and a receiver are used for analyzing light reflected from or transmitted through the work object, and an optical fiber can also deliver the reflected or transmitted light to the detector and/or receiver. The foregoing are merely three examples; many others exist.
Unfortunately, although many fibers are available in the art, it is not unknown for a fiber to fall short of meeting one or more of the performance criteria that can be relevant in a particular application. In many instances, a compromise is made in the design of a fiber wherein one performance characteristic is reduced to ensure higher performance according to another characteristic.
Accordingly it is an object of the present invention to provide an improved optical fiber that addresses one or more of the deficiencies or drawbacks of the prior art.